2. Give the main meanings of the following abbreviations:
cps, lpm, ppm, dpi, pt, USB, CRT, LCD, VDT, VDU, RGB, CMYK, TV, CGA, EGA, VGA, SVGA, COM.
3. Complete the scheme of main printer types.
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rinters
Unit 5 What is Storage?
After reading this unit you should aim to achieve these targets by answering the questions at the end of the unit. You should be able to: - outline main storage devices and terms; - define different disk types, their applications, advantages and disadvantages; - propose your own instructions of caring for computer discs. |
Storage refers to the media and methods used to keep information available for later use. Some things will be needed right away while other won't be needed for extended periods of time. So different methods are appropriate[1] for different uses[2].
Remember from previously all the kinds of things that are stored in Main Memory[3]. Thus [6], Primary Storage is Main Memory This keeps track[4] of what is currently being processed. It's volatile[5]. (power off erases all data)
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Main Memory
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For Main Memory, computers use RAM, or Random Access Memory. This uses memory chips and is the fastest but most expensive type of storage.
Secondary Storage is called Auxiliary Storage[7] |
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This is what is not currently being processed. This is the stuff "filed away"[8], but ready to be pulled out[9] when needed. It is nonvolatile. (power off does not erase)
Auxiliary Storage is used for:
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- data & programs |
Output |
- saving results of processing |
So, Auxiliary Storage is where you put last year's tax info[10], addresses for old customers[11], programs you may or may not ever use, data you entered yesterday - everything that is not being used right now.
Magnetic discs
Of the various types of Auxiliary Storage, the types used most often involve[12] some type of magnetic disk. These come in various sizes and materials, as we shall see. This method uses magnetism to store the data on a magnetic surface.
Advantages: high storage capacity, reliable[13], gives direct access to data[14].
A drive spins the disk very quickly underneath a read/write head, which does what its name says. It reads data from a disk and writes data to a disk. (A name that actually makes sense!)